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This is the schedule for Unit 1 of the Logic Translations and Sentential Logic course. The exam will cover 10 arguments worth 4 points each (40% of the exam) and 12 translations worth 5 points each (60% of the exam). The exam will test your understanding of standard and non-standard connectives in sentential logic.
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INTRO LOGIC TRANSLATIONS IN SENTENTIAL LOGIC2 DAY 06
Schedule for Unit 1 40% of Exam 10 arguments 4 pts each 60% of Exam 12 translations5 pts each
Standard Connectives(have special symbols) and & or not if–then
Non-Standard Connectives(must be paraphrased) …xor… neither-nor if-otherwise …if… unless-in-which-case only if necessary if and only if sufficient unless
Non-Standard Connectives – 1 • xor • or, butnotboth and • ( ) &( & ) • • ( & ) ( & ) exclusive ‘or’
Non-Standard Connectives – 2 neither-nor neithernor notandnot & ( )
Non-Standard Connectives – 3 • if • ifthen • …if…
Non-Standard Connectives – 4 only if onlyif notifnot ifnot then not
Non-Standard Connectives – 5 if and only if if and onlyif if and onlyif ( ) & ( )
Non-Standard Connectives – 6 unless unless if not if not if not then
…if…otherwise… • I will play tennis • if it is sunny; • otherwise, • I will play racketball T if S ;otherwise, R this answers two questions: what will I do if it's sunny? what will I do otherwise(i.e., if it is notsunny)? play tennis play racketball
if – otherwise (cont.) ifit’s sunny, then I’ll play tennis furthermore if it’s not sunny, then I’ll play racketball if S then T and ifnot S then R ( S T ) & ( S R )
…unless…in which case… • I will play tennis unless it rains, • in which case I will play squash T unless R, in which case S this answers two questions: what will I do unless it rains (i.e., if it does not rain)? what will I do in case it rains (i.e., if it doesrain)? play tennis play squash
unless-in-which-case (cont.) ifit doesnot rain, then I’ll play tennis furthermore if it does rain, then I’ll play squash ifR then T and if R then S ( R T ) & ( R S )
Necessary Conditions in order that I get an A it is necessary that I take 4 exams in order for me to get an A it is necessary for me to take 4 exams in order to get an A it is necessary to take 4 exams taking 4 exams is necessary for getting an A
Necessary Conditions (cont) • simplest paraphrase: • is necessary for This amounts to saying if does not happen, thenneither does ifnot thennot
Example taking 4 exams E is necessary forgetting an AA ifE does not happen, thenneither does A ifnot EthennotA EA
Sufficient Conditions in order that I get an A it is sufficient that I get a hundred in order for me to get an A it is sufficient for me to get a hundred in order to get an A it is sufficient to get a hundred getting a hundred is sufficient for getting an A
Sufficient Conditions (cont) • simplest paraphrase: • is sufficient for This amounts to saying ifdoes happen, thensodoes ifthen
Example getting a hundred H is sufficient forgetting an AA ifHdoes happen, thensodoesA ifHthenA HA
Negations Of Necessity getting a hundred His notnecessary for getting an A A not ( H is nec for A ) ifnot H then not A ( H A ) it is not true that ifyou don’tget a hundred then you won’tget an A
Negations of Sufficiency taking all the exams Eis notsufficient forgetting an A A not ( E is suf for A ) if E then A ( E A ) it is not true that ifyou (merely) take all the exams then you will get an A
Basic Statements • is necessary for • is sufficient for • is notnecessary for • is notsufficient for
Combinations • is bothnecessaryandsufficient for • is necessary, butnotsufficient, for • is sufficient, butnotnecessary, for • is neithernecessarynorsufficient for
Example 1 • averaging (at least) fifty A • is bothnecessaryandsufficient for • passing P A is necessary for P ( A P ) and & A is sufficient for P ( A P )
Example 2 • taking four exams E • is necessarybutnotsufficient for • getting an A A E is necessary for A ( E A ) but & E is not sufficient for A ( E A )
Example 3 • getting a hundred H • is sufficientbutnotnecessaryfor • getting an A A H is sufficient for A ( H A ) but & E is not necessary for A ( H A )
Example 4 • attending class A • is neithernecessarynorsufficient for • passing P A is not necessary for P ( A P ) and & A is notsufficient for P ( A P )